Acquisitions, Disposals and Other Transactions - Additional Information (Detail) £ / shares in Units, € in Millions, £ in Millions, AUD in Millions				1 Months Ended						3 Months Ended		6 Months Ended				12 Months Ended
		Sep. 30, 2015 USD ($)	Sep. 30, 2015 GBP (£)	Sep. 30, 2016 USD ($)	Sep. 30, 2016 GBP (£) £ / shares	May 31, 2016 USD ($)	Feb. 29, 2016 USD ($) Tranche	Feb. 29, 2016 AUD Tranche	Jul. 31, 2015 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2016 USD ($)		Dec. 31, 2016 EUR (€)	Dec. 31, 2015 USD ($)	Jun. 30, 2016 USD ($)		Jan. 31, 2016	Sep. 30, 2015 GBP (£)
Schedule Of Business Acquisitions And Divestitures [Line Items]
Restricted cash										$ 0		$ 0				$ 315,000,000
Pre-tax gain of sale of business	[1]									120,000,000	$ 0	$ 120,000,000			$ 0
REA Group [Member]
Schedule Of Business Acquisitions And Divestitures [Line Items]
Company ownership percentage												61.60%		61.60%
Cash consideration of sale of business												$ 140,000,000	[2]	€ 133		0	[2]
Pre-tax gain of sale of business										120,000,000		$ 120,000,000
Checkout 51 Mobile Apps ULC [Member]
Schedule Of Business Acquisitions And Divestitures [Line Items]
Business acquisition, cost of acquired entity									$ 13,000,000
Deferred cash consideration related to contingent payments																10,000,000
DIAKRIT International Limited [Member]
Schedule Of Business Acquisitions And Divestitures [Line Items]
Business acquisition, cost of acquired entity							$ 40,000,000
Business acquisition, acquired interest percentage							92.00%
Non-controlling ownership percentage							8.00%
Number of tranches | Tranche							2	2
Option to sell minority interest, period							6 years	6 years
iProperty Group Limited [Member]
Schedule Of Business Acquisitions And Divestitures [Line Items]
Business acquisition, cost of acquired entity							$ 416,000,000
Business acquisition purchase price allocation, amortizable intangible assets							72,000,000
Business acquisition, cost of acquired entity, cash paid							340,000,000
iProperty Group Limited [Member] | REA Group [Member]
Schedule Of Business Acquisitions And Divestitures [Line Items]
Future consideration related to contingent payments							$ 76,000,000
Non-controlling ownership percentage							13.10%
Business acquisition, ownership percentage							86.90%											22.70%
Business acquisition, cost of acquired entity, cash paid							$ 340,000,000	AUD 482
Minority interest ownership redeemable year												2018		2018
iProperty Group Limited [Member] | REA Group [Member] | Other, Net [Member]
Schedule Of Business Acquisitions And Divestitures [Line Items]
Business acquisition recognized gain resulting from remeasurement of previously held equity interest																$ 29,000,000
Flatmates [Member]
Schedule Of Business Acquisitions And Divestitures [Line Items]
Business acquisition, cost of acquired entity						$ 19,000,000
Future cash consideration related to contingent payments						$ 15,000,000
Wireless Group plc [Member]
Schedule Of Business Acquisitions And Divestitures [Line Items]
Business acquisition, cost of acquired entity				$ 285,000,000	£ 220
Business acquisition, cost of acquired entity per share | £ / shares					£ 0.315
Assumed debt				23,000,000						23,000,000		$ 23,000,000
Restricted cash										0		0
Business acquisition purchase price allocation, amortizable intangible assets				$ 213,000,000
Business acquisition, cost of acquired entity, cash paid												285,000,000
Wireless Group plc [Member] | Broadcast Licenses [Member]
Schedule Of Business Acquisitions And Divestitures [Line Items]
Business acquisition purchase price allocation, non-amortizable intangible assets										178,000,000		178,000,000
Wireless Group plc [Member] | Trademarks [Member]
Schedule Of Business Acquisitions And Divestitures [Line Items]
Business acquisition purchase price allocation, non-amortizable intangible assets										27,000,000		27,000,000
Wireless Group plc [Member] | Customer Relationships [Member]
Schedule Of Business Acquisitions And Divestitures [Line Items]
Business acquisition purchase price allocation, amortizable intangible assets										8,000,000		$ 8,000,000
Finite lived intangible assets, weighted average useful life												6 years		6 years
Unruly Holdings Limited [Member]
Schedule Of Business Acquisitions And Divestitures [Line Items]
Business acquisition, cost of acquired entity		$ 90,000,000	£ 60
Future cash consideration related to contingent payments		86,000,000																	£ 56
Future consideration related to contingent payments		40,000,000
Business acquisition purchase price allocation, goodwill amount		68,000,000
Unruly Holdings Limited [Member] | Acquired Technology [Member]
Schedule Of Business Acquisitions And Divestitures [Line Items]
Business acquisition purchase price allocation, amortizable intangible assets		$ 43,000,000
Finite lived intangible assets, weighted average useful life		7 years	7 years
Unruly Holdings Limited [Member] | Customer Relationships and Trade Names [Member]
Schedule Of Business Acquisitions And Divestitures [Line Items]
Business acquisition purchase price allocation, amortizable intangible assets		$ 21,000,000
Finite lived intangible assets, weighted average useful life		6 years	6 years
Australian Regional Media [Member]
Schedule Of Business Acquisitions And Divestitures [Line Items]
Business acquisition, cost of acquired entity										$ 30,000,000		$ 30,000,000

[1] The Company recorded a $120 million gain resulting from the sale of REA Group's European business. See Note 2-Acquisitions, Disposals and Other Transactions.

[2] See Note 2-Acquisitions, Disposals and Other Transactions.